This research proposal in this application is related to the sponsor's research platform. The sponsor is grant funded (VA RR&D) to begin creation of a comprehensive assessment for phonology in aphasia. The assessment is based on a parallel distributed model of phonology (Nadeau, 2001) and once completed will be a sensitive and specific measure to diagnose phonologic impairment in aphasia. SPECIFIC AIMS: The primary aim of this project is to build ecologically valid items for one subtest of the overall diagnostic batter (e.g repetition). The stimulus items will be tested using recent advances in psychometrics. Rasch analysis will allow for the development and analysis of stimuli at the item level. The following research questions will be addressed: (1) is the repetition item bank unidimensional or does it represent multiple constructs? (2) Does the hypothesized hierarchical structure empirically validate the actual hierarchy? (3) How well does item hierarchy differentiate phonologic dysfunction in individuals with aphasia? RELEVANCE TO PUBLIC HEALTH: This research is directly related to individuals who have suffered a left hemisphere cerebral vascular accident and have subsequent aphasia. This line of work will enhance the clinican's ability to adequately diagnose aphasia which will result in more effective treatment.